Interphase Distribution of Lanthanide Nitrates in Aqueous Organic Two-Phase Systems with Amine and Organic Acid Salts

The extraction of lanthanide nitrates from 0.5 M NaNO3 solutions in 1 : 1 : 1 ternary aqueous organic systems using mixtures of trioctylammonium dialkyl phosphate and dicyclohexylammonium caprylate as extractants was studied. The extractability of lanthanides was shown to increase in the series La < Pr < Nd, Sm, Eu < Gd < Tb < Dy < Ho < Er < Tm, in which the atomic number of the metal increases. The selectivity of extraction in the ternary system was observed during the extraction of heavy lanthanides.